Kawanishi H8K2
Description
Role	Patrol flying boat
Crew	10
First Flight	December 31, 1940
Entered Service	1942
Manufacturer	Kawanishi
Dimensions
Length	28.15 m	92 ft 4 in
Wingspan	38.00 m	124 ft 8 in
Height	9.15 m	30 ft
Wing area	160 m²	1,721 ft²
Weights
Empty	18,380 kg	40,436 lb
Loaded	24,500 kg	53,900 lb
Maximum takeoff	32,500 kg	71,500 lb
Powerplant
Engines	4 × Mitsubishi Kasei 22
Power	5,520 kW	7,400 hp
Performance
Maximum speed	465 km/h	290 mph
Range	7,150 km	4,440 miles
Service ceiling	8,760 m	28,740 ft
Rate of climb	488 m/min	1,600 ft/min
Wing loading	153 kg/m²	31 lb/ft²
Power/Mass	0.22 kW/kg	0.14 hp/lb
Avionics
Radar	Mark VI Model 1
Armament
Guns	1 × 20 mm Type 99 cannon in bow turret 1 × Type 99 cannon in dorsal turret 2 × Type 99 cannon in waist blisters 1 × Type 99 cannon in tail turret 5 × 7.7 mm Type 97 machine guns in fuselage hatches
Stores	2 × 800 kg (1,760 lb) torpedoes or 1,000 kg (2,200 lb) of bombs or depth charges

The Kawanishi H8K (二式大型飛行艇, Type 2 Large Flying Boat. 二式大艇, Nishiki Daitei, Nishiki Taitei) was an Imperial Japanese Navy flying boat used during World War II for maritime patrol duties. The Allied reporting name for the type was Emily.

At the same time as the type's predecessor, the Kawanishi H6K was going into service in 1938, the Navy ordered the development of a larger, longer-range patrol aircraft. The result was a large, shoulder wing design that is widely regarded as the best flying boat of the war. Despite this, development was troublesome, with the prototype displaying terrible handling on the water. Further prototypes considerably refined the hull design.

The H8K entered production in 1941 and first saw operational use on the night of March 4, 1942 in an attempt at a second raid on Pearl Harbor. Since the target lay out of range for the flying boats, this audacious plan involved a refuelling by submarine en route. As it happened, the raid could not be carried out because of problems caused by bad weather.

The improved H8K2 variant soon appeared, and its extremely heavy defensive armament earned it the nickname "Flying Porcupine" among Allied aircrews. This was to be the definitive variant, with 112 produced. They were used on a wide range of patrol, reconnaissance, bombing, and transport missions throughout the Pacific war. Nearly 40 examples of a dedicated transport version, the H8K2-L, were also built, capable of carrying 62 troops. This aircraft was also known as Seiku (晴空, "Calm Sky").

A total of 167 craft were produced, and four survived until the end of the war. One of these, an H8K2, was captured by US forces at the end of the war and was evaluated before being eventually returned to Japan in 1979. It was on display at Tokyo's Museum of Maritime Science until 2004, when it was moved to a museum in Kagoshima.